Sintering Behavior and Electrical Properties of In2O3 Ceramics with ZnO and Sb2O5 Co-Substitution

Zn2+ and Sb5+ were co-doped in In2O3 ceramics. To maintain their charge neutrality, they were substituted for In3+ with a Sb5+:Zn2+ = 1:2 ratio. The solubility limit of the dopants and the phase development, sintering behavior, and electrical characteristics of the co-doped In2O3 specimens were examined. From the X-ray diffraction analysis, the solubility limit was found to have been about 5 at% for Sb and 10 at% for Zn. Over the solubility limit, the beta-Zn7Sb2O12 phase appeared as a second phase. Within the solubility limit, the lattice constant of the In2O3 phase decreased as the amount of the dopants increased. The second phase suppressed the grain growth during the sintering and contributed to the decrease in the electron mobility.